2328 lines
76 KiB
Go
2328 lines
76 KiB
Go
package routing
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import (
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"bytes"
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"crypto/sha256"
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"fmt"
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"runtime"
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"sort"
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"sync"
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"sync/atomic"
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"time"
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"github.com/btcsuite/btcd/btcec"
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"github.com/btcsuite/btcd/wire"
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"github.com/btcsuite/btcutil"
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"github.com/coreos/bbolt"
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"github.com/davecgh/go-spew/spew"
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"github.com/go-errors/errors"
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sphinx "github.com/lightningnetwork/lightning-onion"
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"github.com/lightningnetwork/lnd/channeldb"
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"github.com/lightningnetwork/lnd/htlcswitch"
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"github.com/lightningnetwork/lnd/input"
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"github.com/lightningnetwork/lnd/lnwallet"
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"github.com/lightningnetwork/lnd/lnwire"
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"github.com/lightningnetwork/lnd/multimutex"
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"github.com/lightningnetwork/lnd/routing/chainview"
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"github.com/lightningnetwork/lnd/zpay32"
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)
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const (
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// defaultPayAttemptTimeout is a duration that we'll use to determine
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// if we should give up on a payment attempt. This will be used if a
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// value isn't specified in the LightningNode struct.
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defaultPayAttemptTimeout = time.Duration(time.Second * 60)
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// DefaultChannelPruneExpiry is the default duration used to determine
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// if a channel should be pruned or not.
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DefaultChannelPruneExpiry = time.Duration(time.Hour * 24 * 14)
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)
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var (
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// ErrNoRouteHopsProvided is returned when a caller attempts to
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// construct a new sphinx packet, but provides an empty set of hops for
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// each route.
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ErrNoRouteHopsProvided = fmt.Errorf("empty route hops provided")
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)
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// ChannelGraphSource represents the source of information about the topology
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// of the lightning network. It's responsible for the addition of nodes, edges,
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// applying edge updates, and returning the current block height with which the
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// topology is synchronized.
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type ChannelGraphSource interface {
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// AddNode is used to add information about a node to the router
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// database. If the node with this pubkey is not present in an existing
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// channel, it will be ignored.
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AddNode(node *channeldb.LightningNode) error
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// AddEdge is used to add edge/channel to the topology of the router,
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// after all information about channel will be gathered this
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// edge/channel might be used in construction of payment path.
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AddEdge(edge *channeldb.ChannelEdgeInfo) error
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// AddProof updates the channel edge info with proof which is needed to
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// properly announce the edge to the rest of the network.
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AddProof(chanID lnwire.ShortChannelID, proof *channeldb.ChannelAuthProof) error
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// UpdateEdge is used to update edge information, without this message
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// edge considered as not fully constructed.
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UpdateEdge(policy *channeldb.ChannelEdgePolicy) error
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// IsStaleNode returns true if the graph source has a node announcement
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// for the target node with a more recent timestamp. This method will
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// also return true if we don't have an active channel announcement for
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// the target node.
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IsStaleNode(node Vertex, timestamp time.Time) bool
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// IsPublicNode determines whether the given vertex is seen as a public
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// node in the graph from the graph's source node's point of view.
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IsPublicNode(node Vertex) (bool, error)
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// IsKnownEdge returns true if the graph source already knows of the
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// passed channel ID either as a live or zombie edge.
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IsKnownEdge(chanID lnwire.ShortChannelID) bool
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// IsStaleEdgePolicy returns true if the graph source has a channel
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// edge for the passed channel ID (and flags) that have a more recent
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// timestamp.
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IsStaleEdgePolicy(chanID lnwire.ShortChannelID, timestamp time.Time,
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flags lnwire.ChanUpdateChanFlags) bool
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// MarkEdgeLive clears an edge from our zombie index, deeming it as
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// live.
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MarkEdgeLive(chanID lnwire.ShortChannelID) error
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// ForAllOutgoingChannels is used to iterate over all channels
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// emanating from the "source" node which is the center of the
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// star-graph.
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ForAllOutgoingChannels(cb func(c *channeldb.ChannelEdgeInfo,
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e *channeldb.ChannelEdgePolicy) error) error
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// CurrentBlockHeight returns the block height from POV of the router
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// subsystem.
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CurrentBlockHeight() (uint32, error)
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// GetChannelByID return the channel by the channel id.
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GetChannelByID(chanID lnwire.ShortChannelID) (*channeldb.ChannelEdgeInfo,
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*channeldb.ChannelEdgePolicy, *channeldb.ChannelEdgePolicy, error)
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// FetchLightningNode attempts to look up a target node by its identity
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// public key. channeldb.ErrGraphNodeNotFound is returned if the node
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// doesn't exist within the graph.
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FetchLightningNode(Vertex) (*channeldb.LightningNode, error)
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// ForEachNode is used to iterate over every node in the known graph.
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ForEachNode(func(node *channeldb.LightningNode) error) error
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// ForEachChannel is used to iterate over every channel in the known
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// graph.
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ForEachChannel(func(chanInfo *channeldb.ChannelEdgeInfo,
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e1, e2 *channeldb.ChannelEdgePolicy) error) error
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}
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// FeeSchema is the set fee configuration for a Lightning Node on the network.
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// Using the coefficients described within the schema, the required fee to
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// forward outgoing payments can be derived.
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type FeeSchema struct {
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// BaseFee is the base amount of milli-satoshis that will be chained
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// for ANY payment forwarded.
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BaseFee lnwire.MilliSatoshi
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// FeeRate is the rate that will be charged for forwarding payments.
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// This value should be interpreted as the numerator for a fraction
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// (fixed point arithmetic) whose denominator is 1 million. As a result
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// the effective fee rate charged per mSAT will be: (amount *
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// FeeRate/1,000,000).
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FeeRate uint32
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}
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// ChannelPolicy holds the parameters that determine the policy we enforce
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// when forwarding payments on a channel. These parameters are communicated
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// to the rest of the network in ChannelUpdate messages.
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type ChannelPolicy struct {
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// FeeSchema holds the fee configuration for a channel.
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FeeSchema
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// TimeLockDelta is the required HTLC timelock delta to be used
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// when forwarding payments.
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TimeLockDelta uint32
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}
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// Config defines the configuration for the ChannelRouter. ALL elements within
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// the configuration MUST be non-nil for the ChannelRouter to carry out its
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// duties.
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type Config struct {
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// Graph is the channel graph that the ChannelRouter will use to gather
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// metrics from and also to carry out path finding queries.
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// TODO(roasbeef): make into an interface
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Graph *channeldb.ChannelGraph
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// Chain is the router's source to the most up-to-date blockchain data.
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// All incoming advertised channels will be checked against the chain
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// to ensure that the channels advertised are still open.
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Chain lnwallet.BlockChainIO
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// ChainView is an instance of a FilteredChainView which is used to
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// watch the sub-set of the UTXO set (the set of active channels) that
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// we need in order to properly maintain the channel graph.
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ChainView chainview.FilteredChainView
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// SendToSwitch is a function that directs a link-layer switch to
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// forward a fully encoded payment to the first hop in the route
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// denoted by its public key. A non-nil error is to be returned if the
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// payment was unsuccessful.
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SendToSwitch func(firstHop lnwire.ShortChannelID,
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htlcAdd *lnwire.UpdateAddHTLC,
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circuit *sphinx.Circuit) ([sha256.Size]byte, error)
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// ChannelPruneExpiry is the duration used to determine if a channel
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// should be pruned or not. If the delta between now and when the
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// channel was last updated is greater than ChannelPruneExpiry, then
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// the channel is marked as a zombie channel eligible for pruning.
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ChannelPruneExpiry time.Duration
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// GraphPruneInterval is used as an interval to determine how often we
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// should examine the channel graph to garbage collect zombie channels.
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GraphPruneInterval time.Duration
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// QueryBandwidth is a method that allows the router to query the lower
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// link layer to determine the up to date available bandwidth at a
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// prospective link to be traversed. If the link isn't available, then
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// a value of zero should be returned. Otherwise, the current up to
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// date knowledge of the available bandwidth of the link should be
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// returned.
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QueryBandwidth func(edge *channeldb.ChannelEdgeInfo) lnwire.MilliSatoshi
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// AssumeChannelValid toggles whether or not the router will check for
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// spentness of channel outpoints. For neutrino, this saves long rescans
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// from blocking initial usage of the wallet. This should only be
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// enabled on testnet.
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AssumeChannelValid bool
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}
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// routeTuple is an entry within the ChannelRouter's route cache. We cache
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// prospective routes based on first the destination, and then the target
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// amount. We required the target amount as that will influence the available
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// set of paths for a payment.
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type routeTuple struct {
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amt lnwire.MilliSatoshi
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dest [33]byte
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}
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// newRouteTuple creates a new route tuple from the target and amount.
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func newRouteTuple(amt lnwire.MilliSatoshi, dest []byte) routeTuple {
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r := routeTuple{
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amt: amt,
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}
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copy(r.dest[:], dest)
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return r
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}
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// EdgeLocator is a struct used to identify a specific edge.
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type EdgeLocator struct {
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// ChannelID is the channel of this edge.
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ChannelID uint64
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// Direction takes the value of 0 or 1 and is identical in definition to
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// the channel direction flag. A value of 0 means the direction from the
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// lower node pubkey to the higher.
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Direction uint8
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}
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// newEdgeLocatorByPubkeys returns an edgeLocator based on its end point
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// pubkeys.
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func newEdgeLocatorByPubkeys(channelID uint64, fromNode, toNode *Vertex) *EdgeLocator {
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// Determine direction based on lexicographical ordering of both
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// pubkeys.
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var direction uint8
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if bytes.Compare(fromNode[:], toNode[:]) == 1 {
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direction = 1
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}
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return &EdgeLocator{
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ChannelID: channelID,
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Direction: direction,
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}
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}
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// newEdgeLocator extracts an edgeLocator based for a full edge policy
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// structure.
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func newEdgeLocator(edge *channeldb.ChannelEdgePolicy) *EdgeLocator {
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return &EdgeLocator{
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ChannelID: edge.ChannelID,
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Direction: uint8(edge.ChannelFlags & lnwire.ChanUpdateDirection),
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}
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}
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// String returns a human readable version of the edgeLocator values.
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func (e *EdgeLocator) String() string {
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return fmt.Sprintf("%v:%v", e.ChannelID, e.Direction)
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}
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// ChannelRouter is the layer 3 router within the Lightning stack. Below the
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// ChannelRouter is the HtlcSwitch, and below that is the Bitcoin blockchain
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// itself. The primary role of the ChannelRouter is to respond to queries for
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// potential routes that can support a payment amount, and also general graph
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// reachability questions. The router will prune the channel graph
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// automatically as new blocks are discovered which spend certain known funding
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// outpoints, thereby closing their respective channels.
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type ChannelRouter struct {
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ntfnClientCounter uint64 // To be used atomically.
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started uint32 // To be used atomically.
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stopped uint32 // To be used atomically.
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bestHeight uint32 // To be used atomically.
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// cfg is a copy of the configuration struct that the ChannelRouter was
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// initialized with.
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cfg *Config
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// selfNode is the center of the star-graph centered around the
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// ChannelRouter. The ChannelRouter uses this node as a starting point
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// when doing any path finding.
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selfNode *channeldb.LightningNode
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// routeCache is a map that caches the k-shortest paths from ourselves
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// to a given target destination for a particular payment amount. This
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// map is used as an optimization to speed up subsequent payments to a
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// particular destination. This map will be cleared each time a new
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// channel announcement is accepted, or a new block arrives that
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// results in channels being closed.
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//
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// TODO(roasbeef): make LRU
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routeCacheMtx sync.RWMutex
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routeCache map[routeTuple][]*Route
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// newBlocks is a channel in which new blocks connected to the end of
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// the main chain are sent over, and blocks updated after a call to
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// UpdateFilter.
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newBlocks <-chan *chainview.FilteredBlock
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// staleBlocks is a channel in which blocks disconnected fromt the end
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// of our currently known best chain are sent over.
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staleBlocks <-chan *chainview.FilteredBlock
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// networkUpdates is a channel that carries new topology updates
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// messages from outside the ChannelRouter to be processed by the
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// networkHandler.
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networkUpdates chan *routingMsg
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// topologyClients maps a client's unique notification ID to a
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// topologyClient client that contains its notification dispatch
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// channel.
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topologyClients map[uint64]*topologyClient
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// ntfnClientUpdates is a channel that's used to send new updates to
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// topology notification clients to the ChannelRouter. Updates either
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// add a new notification client, or cancel notifications for an
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// existing client.
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ntfnClientUpdates chan *topologyClientUpdate
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// missionControl is a shared memory of sorts that executions of
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// payment path finding use in order to remember which vertexes/edges
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// were pruned from prior attempts. During SendPayment execution,
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// errors sent by nodes are mapped into a vertex or edge to be pruned.
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// Each run will then take into account this set of pruned
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// vertexes/edges to reduce route failure and pass on graph information
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// gained to the next execution.
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missionControl *missionControl
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// channelEdgeMtx is a mutex we use to make sure we process only one
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// ChannelEdgePolicy at a time for a given channelID, to ensure
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// consistency between the various database accesses.
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channelEdgeMtx *multimutex.Mutex
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rejectMtx sync.RWMutex
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rejectCache map[uint64]struct{}
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sync.RWMutex
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quit chan struct{}
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wg sync.WaitGroup
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}
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// A compile time check to ensure ChannelRouter implements the
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// ChannelGraphSource interface.
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var _ ChannelGraphSource = (*ChannelRouter)(nil)
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// New creates a new instance of the ChannelRouter with the specified
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// configuration parameters. As part of initialization, if the router detects
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// that the channel graph isn't fully in sync with the latest UTXO (since the
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// channel graph is a subset of the UTXO set) set, then the router will proceed
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// to fully sync to the latest state of the UTXO set.
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func New(cfg Config) (*ChannelRouter, error) {
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selfNode, err := cfg.Graph.SourceNode()
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if err != nil {
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return nil, err
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}
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r := &ChannelRouter{
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cfg: &cfg,
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networkUpdates: make(chan *routingMsg),
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topologyClients: make(map[uint64]*topologyClient),
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ntfnClientUpdates: make(chan *topologyClientUpdate),
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channelEdgeMtx: multimutex.NewMutex(),
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selfNode: selfNode,
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routeCache: make(map[routeTuple][]*Route),
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rejectCache: make(map[uint64]struct{}),
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quit: make(chan struct{}),
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}
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r.missionControl = newMissionControl(
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cfg.Graph, selfNode, cfg.QueryBandwidth,
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)
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return r, nil
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}
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// Start launches all the goroutines the ChannelRouter requires to carry out
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// its duties. If the router has already been started, then this method is a
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// noop.
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func (r *ChannelRouter) Start() error {
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if !atomic.CompareAndSwapUint32(&r.started, 0, 1) {
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return nil
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}
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log.Tracef("Channel Router starting")
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|
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// First, we'll start the chain view instance (if it isn't already
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// started).
|
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if err := r.cfg.ChainView.Start(); err != nil {
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return err
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}
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|
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// Once the instance is active, we'll fetch the channel we'll receive
|
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// notifications over.
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r.newBlocks = r.cfg.ChainView.FilteredBlocks()
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r.staleBlocks = r.cfg.ChainView.DisconnectedBlocks()
|
|
|
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bestHash, bestHeight, err := r.cfg.Chain.GetBestBlock()
|
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if err != nil {
|
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return err
|
|
}
|
|
|
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if _, _, err := r.cfg.Graph.PruneTip(); err != nil {
|
|
switch {
|
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// If the graph has never been pruned, or hasn't fully been
|
|
// created yet, then we don't treat this as an explicit error.
|
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case err == channeldb.ErrGraphNeverPruned:
|
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fallthrough
|
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case err == channeldb.ErrGraphNotFound:
|
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// If the graph has never been pruned, then we'll set
|
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// the prune height to the current best height of the
|
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// chain backend.
|
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_, err = r.cfg.Graph.PruneGraph(
|
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nil, bestHash, uint32(bestHeight),
|
|
)
|
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if err != nil {
|
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return err
|
|
}
|
|
default:
|
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return err
|
|
}
|
|
}
|
|
|
|
// Before we perform our manual block pruning, we'll construct and
|
|
// apply a fresh chain filter to the active FilteredChainView instance.
|
|
// We do this before, as otherwise we may miss on-chain events as the
|
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// filter hasn't properly been applied.
|
|
channelView, err := r.cfg.Graph.ChannelView()
|
|
if err != nil && err != channeldb.ErrGraphNoEdgesFound {
|
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return err
|
|
}
|
|
|
|
log.Infof("Filtering chain using %v channels active", len(channelView))
|
|
if len(channelView) != 0 {
|
|
err = r.cfg.ChainView.UpdateFilter(
|
|
channelView, uint32(bestHeight),
|
|
)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
}
|
|
|
|
// Before we begin normal operation of the router, we first need to
|
|
// synchronize the channel graph to the latest state of the UTXO set.
|
|
if err := r.syncGraphWithChain(); err != nil {
|
|
return err
|
|
}
|
|
|
|
// Finally, before we proceed, we'll prune any unconnected nodes from
|
|
// the graph in order to ensure we maintain a tight graph of "useful"
|
|
// nodes.
|
|
err = r.cfg.Graph.PruneGraphNodes()
|
|
if err != nil && err != channeldb.ErrGraphNodesNotFound {
|
|
return err
|
|
}
|
|
|
|
r.wg.Add(1)
|
|
go r.networkHandler()
|
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|
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return nil
|
|
}
|
|
|
|
// Stop signals the ChannelRouter to gracefully halt all routines. This method
|
|
// will *block* until all goroutines have excited. If the channel router has
|
|
// already stopped then this method will return immediately.
|
|
func (r *ChannelRouter) Stop() error {
|
|
if !atomic.CompareAndSwapUint32(&r.stopped, 0, 1) {
|
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return nil
|
|
}
|
|
|
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log.Infof("Channel Router shutting down")
|
|
|
|
if err := r.cfg.ChainView.Stop(); err != nil {
|
|
return err
|
|
}
|
|
|
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close(r.quit)
|
|
r.wg.Wait()
|
|
|
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return nil
|
|
}
|
|
|
|
// syncGraphWithChain attempts to synchronize the current channel graph with
|
|
// the latest UTXO set state. This process involves pruning from the channel
|
|
// graph any channels which have been closed by spending their funding output
|
|
// since we've been down.
|
|
func (r *ChannelRouter) syncGraphWithChain() error {
|
|
// First, we'll need to check to see if we're already in sync with the
|
|
// latest state of the UTXO set.
|
|
bestHash, bestHeight, err := r.cfg.Chain.GetBestBlock()
|
|
if err != nil {
|
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return err
|
|
}
|
|
r.bestHeight = uint32(bestHeight)
|
|
|
|
pruneHash, pruneHeight, err := r.cfg.Graph.PruneTip()
|
|
if err != nil {
|
|
switch {
|
|
// If the graph has never been pruned, or hasn't fully been
|
|
// created yet, then we don't treat this as an explicit error.
|
|
case err == channeldb.ErrGraphNeverPruned:
|
|
case err == channeldb.ErrGraphNotFound:
|
|
default:
|
|
return err
|
|
}
|
|
}
|
|
|
|
log.Infof("Prune tip for Channel Graph: height=%v, hash=%v", pruneHeight,
|
|
pruneHash)
|
|
|
|
switch {
|
|
|
|
// If the graph has never been pruned, then we can exit early as this
|
|
// entails it's being created for the first time and hasn't seen any
|
|
// block or created channels.
|
|
case pruneHeight == 0 || pruneHash == nil:
|
|
return nil
|
|
|
|
// If the block hashes and heights match exactly, then we don't need to
|
|
// prune the channel graph as we're already fully in sync.
|
|
case bestHash.IsEqual(pruneHash) && uint32(bestHeight) == pruneHeight:
|
|
return nil
|
|
}
|
|
|
|
// If the main chain blockhash at prune height is different from the
|
|
// prune hash, this might indicate the database is on a stale branch.
|
|
mainBlockHash, err := r.cfg.Chain.GetBlockHash(int64(pruneHeight))
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
// While we are on a stale branch of the chain, walk backwards to find
|
|
// first common block.
|
|
for !pruneHash.IsEqual(mainBlockHash) {
|
|
log.Infof("channel graph is stale. Disconnecting block %v "+
|
|
"(hash=%v)", pruneHeight, pruneHash)
|
|
// Prune the graph for every channel that was opened at height
|
|
// >= pruneHeight.
|
|
_, err := r.cfg.Graph.DisconnectBlockAtHeight(pruneHeight)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
pruneHash, pruneHeight, err = r.cfg.Graph.PruneTip()
|
|
if err != nil {
|
|
switch {
|
|
// If at this point the graph has never been pruned, we
|
|
// can exit as this entails we are back to the point
|
|
// where it hasn't seen any block or created channels,
|
|
// alas there's nothing left to prune.
|
|
case err == channeldb.ErrGraphNeverPruned:
|
|
return nil
|
|
case err == channeldb.ErrGraphNotFound:
|
|
return nil
|
|
default:
|
|
return err
|
|
}
|
|
}
|
|
mainBlockHash, err = r.cfg.Chain.GetBlockHash(int64(pruneHeight))
|
|
if err != nil {
|
|
return err
|
|
}
|
|
}
|
|
|
|
log.Infof("Syncing channel graph from height=%v (hash=%v) to height=%v "+
|
|
"(hash=%v)", pruneHeight, pruneHash, bestHeight, bestHash)
|
|
|
|
// If we're not yet caught up, then we'll walk forward in the chain in
|
|
// the chain pruning the channel graph with each new block in the chain
|
|
// that hasn't yet been consumed by the channel graph.
|
|
var numChansClosed uint32
|
|
for nextHeight := pruneHeight + 1; nextHeight <= uint32(bestHeight); nextHeight++ {
|
|
// Using the next height, request a manual block pruning from
|
|
// the chainview for the particular block hash.
|
|
nextHash, err := r.cfg.Chain.GetBlockHash(int64(nextHeight))
|
|
if err != nil {
|
|
return err
|
|
}
|
|
filterBlock, err := r.cfg.ChainView.FilterBlock(nextHash)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
// We're only interested in all prior outputs that have been
|
|
// spent in the block, so collate all the referenced previous
|
|
// outpoints within each tx and input.
|
|
var spentOutputs []*wire.OutPoint
|
|
for _, tx := range filterBlock.Transactions {
|
|
for _, txIn := range tx.TxIn {
|
|
spentOutputs = append(spentOutputs,
|
|
&txIn.PreviousOutPoint)
|
|
}
|
|
}
|
|
|
|
// With the spent outputs gathered, attempt to prune the
|
|
// channel graph, also passing in the hash+height of the block
|
|
// being pruned so the prune tip can be updated.
|
|
closedChans, err := r.cfg.Graph.PruneGraph(spentOutputs,
|
|
nextHash,
|
|
nextHeight)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
numClosed := uint32(len(closedChans))
|
|
log.Infof("Block %v (height=%v) closed %v channels",
|
|
nextHash, nextHeight, numClosed)
|
|
|
|
numChansClosed += numClosed
|
|
}
|
|
|
|
log.Infof("Graph pruning complete: %v channels were closed since "+
|
|
"height %v", numChansClosed, pruneHeight)
|
|
return nil
|
|
}
|
|
|
|
// pruneZombieChans is a method that will be called periodically to prune out
|
|
// any "zombie" channels. We consider channels zombies if *both* edges haven't
|
|
// been updated since our zombie horizon. We do this periodically to keep a
|
|
// health, lively routing table.
|
|
func (r *ChannelRouter) pruneZombieChans() error {
|
|
var chansToPrune []wire.OutPoint
|
|
chanExpiry := r.cfg.ChannelPruneExpiry
|
|
|
|
log.Infof("Examining Channel Graph for zombie channels")
|
|
|
|
// First, we'll collect all the channels which are eligible for garbage
|
|
// collection due to being zombies.
|
|
filterPruneChans := func(info *channeldb.ChannelEdgeInfo,
|
|
e1, e2 *channeldb.ChannelEdgePolicy) error {
|
|
|
|
// We'll ensure that we don't attempt to prune our *own*
|
|
// channels from the graph, as in any case this should be
|
|
// re-advertised by the sub-system above us.
|
|
if info.NodeKey1Bytes == r.selfNode.PubKeyBytes ||
|
|
info.NodeKey2Bytes == r.selfNode.PubKeyBytes {
|
|
|
|
return nil
|
|
}
|
|
|
|
// If *both* edges haven't been updated for a period of
|
|
// chanExpiry, then we'll mark the channel itself as eligible
|
|
// for graph pruning.
|
|
e1Zombie, e2Zombie := true, true
|
|
if e1 != nil {
|
|
e1Zombie = time.Since(e1.LastUpdate) >= chanExpiry
|
|
if e1Zombie {
|
|
log.Tracef("Edge #1 of ChannelPoint(%v) "+
|
|
"last update: %v",
|
|
info.ChannelPoint, e1.LastUpdate)
|
|
}
|
|
}
|
|
if e2 != nil {
|
|
e2Zombie = time.Since(e2.LastUpdate) >= chanExpiry
|
|
if e2Zombie {
|
|
log.Tracef("Edge #2 of ChannelPoint(%v) "+
|
|
"last update: %v",
|
|
info.ChannelPoint, e2.LastUpdate)
|
|
}
|
|
}
|
|
if e1Zombie && e2Zombie {
|
|
log.Debugf("ChannelPoint(%v) is a zombie, collecting "+
|
|
"to prune", info.ChannelPoint)
|
|
|
|
// TODO(roasbeef): add ability to delete single
|
|
// directional edge
|
|
chansToPrune = append(chansToPrune, info.ChannelPoint)
|
|
|
|
// As we're detecting this as a zombie channel, we'll
|
|
// add this to the set of recently rejected items so we
|
|
// don't re-accept it shortly after.
|
|
r.rejectCache[info.ChannelID] = struct{}{}
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
r.rejectMtx.Lock()
|
|
defer r.rejectMtx.Unlock()
|
|
|
|
err := r.cfg.Graph.ForEachChannel(filterPruneChans)
|
|
if err != nil {
|
|
return fmt.Errorf("Unable to filter local zombie "+
|
|
"chans: %v", err)
|
|
}
|
|
|
|
log.Infof("Pruning %v Zombie Channels", len(chansToPrune))
|
|
|
|
// With the set zombie-like channels obtained, we'll do another pass to
|
|
// delete al zombie channels from the channel graph.
|
|
for _, chanToPrune := range chansToPrune {
|
|
log.Tracef("Pruning zombie chan ChannelPoint(%v)", chanToPrune)
|
|
|
|
err := r.cfg.Graph.DeleteChannelEdge(&chanToPrune)
|
|
if err != nil {
|
|
return fmt.Errorf("Unable to prune zombie "+
|
|
"chans: %v", err)
|
|
}
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
// networkHandler is the primary goroutine for the ChannelRouter. The roles of
|
|
// this goroutine include answering queries related to the state of the
|
|
// network, pruning the graph on new block notification, applying network
|
|
// updates, and registering new topology clients.
|
|
//
|
|
// NOTE: This MUST be run as a goroutine.
|
|
func (r *ChannelRouter) networkHandler() {
|
|
defer r.wg.Done()
|
|
|
|
graphPruneTicker := time.NewTicker(r.cfg.GraphPruneInterval)
|
|
defer graphPruneTicker.Stop()
|
|
|
|
// We'll use this validation barrier to ensure that we process all jobs
|
|
// in the proper order during parallel validation.
|
|
validationBarrier := NewValidationBarrier(runtime.NumCPU()*4, r.quit)
|
|
|
|
for {
|
|
select {
|
|
// A new fully validated network update has just arrived. As a
|
|
// result we'll modify the channel graph accordingly depending
|
|
// on the exact type of the message.
|
|
case update := <-r.networkUpdates:
|
|
// We'll set up any dependants, and wait until a free
|
|
// slot for this job opens up, this allow us to not
|
|
// have thousands of goroutines active.
|
|
validationBarrier.InitJobDependencies(update.msg)
|
|
|
|
r.wg.Add(1)
|
|
go func() {
|
|
defer r.wg.Done()
|
|
defer validationBarrier.CompleteJob()
|
|
|
|
// If this message has an existing dependency,
|
|
// then we'll wait until that has been fully
|
|
// validated before we proceed.
|
|
err := validationBarrier.WaitForDependants(
|
|
update.msg,
|
|
)
|
|
if err != nil {
|
|
if err != ErrVBarrierShuttingDown {
|
|
log.Warnf("unexpected error "+
|
|
"during validation "+
|
|
"barrier shutdown: %v",
|
|
err)
|
|
}
|
|
return
|
|
}
|
|
|
|
// Process the routing update to determine if
|
|
// this is either a new update from our PoV or
|
|
// an update to a prior vertex/edge we
|
|
// previously accepted.
|
|
err = r.processUpdate(update.msg)
|
|
update.err <- err
|
|
|
|
// If this message had any dependencies, then
|
|
// we can now signal them to continue.
|
|
validationBarrier.SignalDependants(update.msg)
|
|
if err != nil {
|
|
return
|
|
}
|
|
|
|
// Send off a new notification for the newly
|
|
// accepted update.
|
|
topChange := &TopologyChange{}
|
|
err = addToTopologyChange(
|
|
r.cfg.Graph, topChange, update.msg,
|
|
)
|
|
if err != nil {
|
|
log.Errorf("unable to update topology "+
|
|
"change notification: %v", err)
|
|
return
|
|
}
|
|
|
|
if !topChange.isEmpty() {
|
|
r.notifyTopologyChange(topChange)
|
|
}
|
|
}()
|
|
|
|
// TODO(roasbeef): remove all unconnected vertexes
|
|
// after N blocks pass with no corresponding
|
|
// announcements.
|
|
|
|
case chainUpdate, ok := <-r.staleBlocks:
|
|
// If the channel has been closed, then this indicates
|
|
// the daemon is shutting down, so we exit ourselves.
|
|
if !ok {
|
|
return
|
|
}
|
|
|
|
// Since this block is stale, we update our best height
|
|
// to the previous block.
|
|
blockHeight := uint32(chainUpdate.Height)
|
|
atomic.StoreUint32(&r.bestHeight, blockHeight-1)
|
|
|
|
// Update the channel graph to reflect that this block
|
|
// was disconnected.
|
|
_, err := r.cfg.Graph.DisconnectBlockAtHeight(blockHeight)
|
|
if err != nil {
|
|
log.Errorf("unable to prune graph with stale "+
|
|
"block: %v", err)
|
|
continue
|
|
}
|
|
|
|
// Invalidate the route cache, as some channels might
|
|
// not be confirmed anymore.
|
|
r.routeCacheMtx.Lock()
|
|
r.routeCache = make(map[routeTuple][]*Route)
|
|
r.routeCacheMtx.Unlock()
|
|
|
|
// TODO(halseth): notify client about the reorg?
|
|
|
|
// A new block has arrived, so we can prune the channel graph
|
|
// of any channels which were closed in the block.
|
|
case chainUpdate, ok := <-r.newBlocks:
|
|
// If the channel has been closed, then this indicates
|
|
// the daemon is shutting down, so we exit ourselves.
|
|
if !ok {
|
|
return
|
|
}
|
|
|
|
// We'll ensure that any new blocks received attach
|
|
// directly to the end of our main chain. If not, then
|
|
// we've somehow missed some blocks. We don't process
|
|
// this block as otherwise, we may miss on-chain
|
|
// events.
|
|
currentHeight := atomic.LoadUint32(&r.bestHeight)
|
|
if chainUpdate.Height != currentHeight+1 {
|
|
log.Errorf("out of order block: expecting "+
|
|
"height=%v, got height=%v", currentHeight+1,
|
|
chainUpdate.Height)
|
|
continue
|
|
}
|
|
|
|
// Once a new block arrives, we update our running
|
|
// track of the height of the chain tip.
|
|
blockHeight := uint32(chainUpdate.Height)
|
|
atomic.StoreUint32(&r.bestHeight, blockHeight)
|
|
log.Infof("Pruning channel graph using block %v (height=%v)",
|
|
chainUpdate.Hash, blockHeight)
|
|
|
|
// We're only interested in all prior outputs that have
|
|
// been spent in the block, so collate all the
|
|
// referenced previous outpoints within each tx and
|
|
// input.
|
|
var spentOutputs []*wire.OutPoint
|
|
for _, tx := range chainUpdate.Transactions {
|
|
for _, txIn := range tx.TxIn {
|
|
spentOutputs = append(spentOutputs,
|
|
&txIn.PreviousOutPoint)
|
|
}
|
|
}
|
|
|
|
// With the spent outputs gathered, attempt to prune
|
|
// the channel graph, also passing in the hash+height
|
|
// of the block being pruned so the prune tip can be
|
|
// updated.
|
|
chansClosed, err := r.cfg.Graph.PruneGraph(spentOutputs,
|
|
&chainUpdate.Hash, chainUpdate.Height)
|
|
if err != nil {
|
|
log.Errorf("unable to prune routing table: %v", err)
|
|
continue
|
|
}
|
|
|
|
log.Infof("Block %v (height=%v) closed %v channels",
|
|
chainUpdate.Hash, blockHeight, len(chansClosed))
|
|
|
|
// Invalidate the route cache as the block height has
|
|
// changed which will invalidate the HTLC timeouts we
|
|
// have crafted within each of the pre-computed routes.
|
|
//
|
|
// TODO(roasbeef): need to invalidate after each
|
|
// chan ann update?
|
|
// * can have map of chanID to routes involved, avoids
|
|
// full invalidation
|
|
r.routeCacheMtx.Lock()
|
|
r.routeCache = make(map[routeTuple][]*Route)
|
|
r.routeCacheMtx.Unlock()
|
|
|
|
if len(chansClosed) == 0 {
|
|
continue
|
|
}
|
|
|
|
// Notify all currently registered clients of the newly
|
|
// closed channels.
|
|
closeSummaries := createCloseSummaries(blockHeight, chansClosed...)
|
|
r.notifyTopologyChange(&TopologyChange{
|
|
ClosedChannels: closeSummaries,
|
|
})
|
|
|
|
// A new notification client update has arrived. We're either
|
|
// gaining a new client, or cancelling notifications for an
|
|
// existing client.
|
|
case ntfnUpdate := <-r.ntfnClientUpdates:
|
|
clientID := ntfnUpdate.clientID
|
|
|
|
if ntfnUpdate.cancel {
|
|
r.RLock()
|
|
client, ok := r.topologyClients[ntfnUpdate.clientID]
|
|
r.RUnlock()
|
|
if ok {
|
|
r.Lock()
|
|
delete(r.topologyClients, clientID)
|
|
r.Unlock()
|
|
|
|
close(client.exit)
|
|
client.wg.Wait()
|
|
|
|
close(client.ntfnChan)
|
|
}
|
|
|
|
continue
|
|
}
|
|
|
|
r.Lock()
|
|
r.topologyClients[ntfnUpdate.clientID] = &topologyClient{
|
|
ntfnChan: ntfnUpdate.ntfnChan,
|
|
exit: make(chan struct{}),
|
|
}
|
|
r.Unlock()
|
|
|
|
// The graph prune ticker has ticked, so we'll examine the
|
|
// state of the known graph to filter out any zombie channels
|
|
// for pruning.
|
|
case <-graphPruneTicker.C:
|
|
if err := r.pruneZombieChans(); err != nil {
|
|
log.Errorf("unable to prune zombies: %v", err)
|
|
}
|
|
|
|
// The router has been signalled to exit, to we exit our main
|
|
// loop so the wait group can be decremented.
|
|
case <-r.quit:
|
|
return
|
|
}
|
|
}
|
|
}
|
|
|
|
// assertNodeAnnFreshness returns a non-nil error if we have an announcement in
|
|
// the database for the passed node with a timestamp newer than the passed
|
|
// timestamp. ErrIgnored will be returned if we already have the node, and
|
|
// ErrOutdated will be returned if we have a timestamp that's after the new
|
|
// timestamp.
|
|
func (r *ChannelRouter) assertNodeAnnFreshness(node Vertex,
|
|
msgTimestamp time.Time) error {
|
|
|
|
// If we are not already aware of this node, it means that we don't
|
|
// know about any channel using this node. To avoid a DoS attack by
|
|
// node announcements, we will ignore such nodes. If we do know about
|
|
// this node, check that this update brings info newer than what we
|
|
// already have.
|
|
lastUpdate, exists, err := r.cfg.Graph.HasLightningNode(node)
|
|
if err != nil {
|
|
return errors.Errorf("unable to query for the "+
|
|
"existence of node: %v", err)
|
|
}
|
|
if !exists {
|
|
return newErrf(ErrIgnored, "Ignoring node announcement"+
|
|
" for node not found in channel graph (%x)",
|
|
node[:])
|
|
}
|
|
|
|
// If we've reached this point then we're aware of the vertex being
|
|
// advertised. So we now check if the new message has a new time stamp,
|
|
// if not then we won't accept the new data as it would override newer
|
|
// data.
|
|
if !lastUpdate.Before(msgTimestamp) {
|
|
return newErrf(ErrOutdated, "Ignoring outdated "+
|
|
"announcement for %x", node[:])
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
// processUpdate processes a new relate authenticated channel/edge, node or
|
|
// channel/edge update network update. If the update didn't affect the internal
|
|
// state of the draft due to either being out of date, invalid, or redundant,
|
|
// then error is returned.
|
|
func (r *ChannelRouter) processUpdate(msg interface{}) error {
|
|
|
|
var invalidateCache bool
|
|
|
|
switch msg := msg.(type) {
|
|
case *channeldb.LightningNode:
|
|
// Before we add the node to the database, we'll check to see
|
|
// if the announcement is "fresh" or not. If it isn't, then
|
|
// we'll return an error.
|
|
err := r.assertNodeAnnFreshness(msg.PubKeyBytes, msg.LastUpdate)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
if err := r.cfg.Graph.AddLightningNode(msg); err != nil {
|
|
return errors.Errorf("unable to add node %v to the "+
|
|
"graph: %v", msg.PubKeyBytes, err)
|
|
}
|
|
|
|
log.Infof("Updated vertex data for node=%x", msg.PubKeyBytes)
|
|
|
|
case *channeldb.ChannelEdgeInfo:
|
|
// If we recently rejected this channel edge, then we won't
|
|
// attempt to re-process it.
|
|
r.rejectMtx.RLock()
|
|
if _, ok := r.rejectCache[msg.ChannelID]; ok {
|
|
r.rejectMtx.RUnlock()
|
|
return newErrf(ErrRejected, "recently rejected "+
|
|
"chan_id=%v", msg.ChannelID)
|
|
}
|
|
r.rejectMtx.RUnlock()
|
|
|
|
// Prior to processing the announcement we first check if we
|
|
// already know of this channel, if so, then we can exit early.
|
|
_, _, exists, isZombie, err := r.cfg.Graph.HasChannelEdge(
|
|
msg.ChannelID,
|
|
)
|
|
if err != nil && err != channeldb.ErrGraphNoEdgesFound {
|
|
return errors.Errorf("unable to check for edge "+
|
|
"existence: %v", err)
|
|
}
|
|
if isZombie {
|
|
return newErrf(ErrIgnored, "ignoring msg for zombie "+
|
|
"chan_id=%v", msg.ChannelID)
|
|
}
|
|
if exists {
|
|
return newErrf(ErrIgnored, "ignoring msg for known "+
|
|
"chan_id=%v", msg.ChannelID)
|
|
}
|
|
|
|
// Before we can add the channel to the channel graph, we need
|
|
// to obtain the full funding outpoint that's encoded within
|
|
// the channel ID.
|
|
channelID := lnwire.NewShortChanIDFromInt(msg.ChannelID)
|
|
fundingPoint, fundingTxOut, err := r.fetchChanPoint(&channelID)
|
|
if err != nil {
|
|
r.rejectMtx.Lock()
|
|
r.rejectCache[msg.ChannelID] = struct{}{}
|
|
r.rejectMtx.Unlock()
|
|
|
|
return errors.Errorf("unable to fetch chan point for "+
|
|
"chan_id=%v: %v", msg.ChannelID, err)
|
|
}
|
|
|
|
// Recreate witness output to be sure that declared in channel
|
|
// edge bitcoin keys and channel value corresponds to the
|
|
// reality.
|
|
witnessScript, err := input.GenMultiSigScript(
|
|
msg.BitcoinKey1Bytes[:], msg.BitcoinKey2Bytes[:],
|
|
)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
fundingPkScript, err := input.WitnessScriptHash(witnessScript)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
var chanUtxo *wire.TxOut
|
|
if r.cfg.AssumeChannelValid {
|
|
// If AssumeChannelValid is present, we'll just use the
|
|
// txout returned from fetchChanPoint.
|
|
chanUtxo = fundingTxOut
|
|
} else {
|
|
// Now that we have the funding outpoint of the channel,
|
|
// ensure that it hasn't yet been spent. If so, then
|
|
// this channel has been closed so we'll ignore it.
|
|
chanUtxo, err = r.cfg.Chain.GetUtxo(
|
|
fundingPoint, fundingPkScript,
|
|
channelID.BlockHeight,
|
|
)
|
|
if err != nil {
|
|
r.rejectMtx.Lock()
|
|
r.rejectCache[msg.ChannelID] = struct{}{}
|
|
r.rejectMtx.Unlock()
|
|
|
|
return errors.Errorf("unable to fetch utxo "+
|
|
"for chan_id=%v, chan_point=%v: %v",
|
|
msg.ChannelID, fundingPoint, err)
|
|
}
|
|
}
|
|
|
|
// By checking the equality of witness pkscripts we checks that
|
|
// funding witness script is multisignature lock which contains
|
|
// both local and remote public keys which was declared in
|
|
// channel edge and also that the announced channel value is
|
|
// right.
|
|
if !bytes.Equal(fundingPkScript, chanUtxo.PkScript) {
|
|
return errors.Errorf("pkScript mismatch: expected %x, "+
|
|
"got %x", fundingPkScript, chanUtxo.PkScript)
|
|
}
|
|
|
|
// TODO(roasbeef): this is a hack, needs to be removed
|
|
// after commitment fees are dynamic.
|
|
msg.Capacity = btcutil.Amount(chanUtxo.Value)
|
|
msg.ChannelPoint = *fundingPoint
|
|
if err := r.cfg.Graph.AddChannelEdge(msg); err != nil {
|
|
return errors.Errorf("unable to add edge: %v", err)
|
|
}
|
|
|
|
invalidateCache = true
|
|
log.Infof("New channel discovered! Link "+
|
|
"connects %x and %x with ChannelPoint(%v): "+
|
|
"chan_id=%v, capacity=%v",
|
|
msg.NodeKey1Bytes, msg.NodeKey2Bytes,
|
|
fundingPoint, msg.ChannelID, msg.Capacity)
|
|
|
|
// As a new edge has been added to the channel graph, we'll
|
|
// update the current UTXO filter within our active
|
|
// FilteredChainView so we are notified if/when this channel is
|
|
// closed.
|
|
filterUpdate := []channeldb.EdgePoint{
|
|
{
|
|
FundingPkScript: fundingPkScript,
|
|
OutPoint: *fundingPoint,
|
|
},
|
|
}
|
|
err = r.cfg.ChainView.UpdateFilter(
|
|
filterUpdate, atomic.LoadUint32(&r.bestHeight),
|
|
)
|
|
if err != nil {
|
|
return errors.Errorf("unable to update chain "+
|
|
"view: %v", err)
|
|
}
|
|
|
|
case *channeldb.ChannelEdgePolicy:
|
|
// If we recently rejected this channel edge, then we won't
|
|
// attempt to re-process it.
|
|
r.rejectMtx.RLock()
|
|
if _, ok := r.rejectCache[msg.ChannelID]; ok {
|
|
r.rejectMtx.RUnlock()
|
|
return newErrf(ErrRejected, "recently rejected "+
|
|
"chan_id=%v", msg.ChannelID)
|
|
}
|
|
r.rejectMtx.RUnlock()
|
|
|
|
// We make sure to hold the mutex for this channel ID,
|
|
// such that no other goroutine is concurrently doing
|
|
// database accesses for the same channel ID.
|
|
r.channelEdgeMtx.Lock(msg.ChannelID)
|
|
defer r.channelEdgeMtx.Unlock(msg.ChannelID)
|
|
|
|
edge1Timestamp, edge2Timestamp, exists, isZombie, err :=
|
|
r.cfg.Graph.HasChannelEdge(msg.ChannelID)
|
|
if err != nil && err != channeldb.ErrGraphNoEdgesFound {
|
|
return errors.Errorf("unable to check for edge "+
|
|
"existence: %v", err)
|
|
|
|
}
|
|
|
|
// If the channel is marked as a zombie in our database, and
|
|
// we consider this a stale update, then we should not apply the
|
|
// policy.
|
|
isStaleUpdate := time.Since(msg.LastUpdate) > r.cfg.ChannelPruneExpiry
|
|
if isZombie && isStaleUpdate {
|
|
return newErrf(ErrIgnored, "ignoring stale update "+
|
|
"(flags=%v|%v) for zombie chan_id=%v",
|
|
msg.MessageFlags, msg.ChannelFlags,
|
|
msg.ChannelID)
|
|
}
|
|
|
|
// If the channel doesn't exist in our database, we cannot
|
|
// apply the updated policy.
|
|
if !exists {
|
|
return newErrf(ErrIgnored, "ignoring update "+
|
|
"(flags=%v|%v) for unknown chan_id=%v",
|
|
msg.MessageFlags, msg.ChannelFlags,
|
|
msg.ChannelID)
|
|
}
|
|
|
|
// As edges are directional edge node has a unique policy for
|
|
// the direction of the edge they control. Therefore we first
|
|
// check if we already have the most up to date information for
|
|
// that edge. If this message has a timestamp not strictly
|
|
// newer than what we already know of we can exit early.
|
|
switch {
|
|
|
|
// A flag set of 0 indicates this is an announcement for the
|
|
// "first" node in the channel.
|
|
case msg.ChannelFlags&lnwire.ChanUpdateDirection == 0:
|
|
|
|
// Ignore outdated message.
|
|
if !edge1Timestamp.Before(msg.LastUpdate) {
|
|
return newErrf(ErrOutdated, "Ignoring "+
|
|
"outdated update (flags=%v|%v) for "+
|
|
"known chan_id=%v", msg.MessageFlags,
|
|
msg.ChannelFlags, msg.ChannelID)
|
|
}
|
|
|
|
// Similarly, a flag set of 1 indicates this is an announcement
|
|
// for the "second" node in the channel.
|
|
case msg.ChannelFlags&lnwire.ChanUpdateDirection == 1:
|
|
|
|
// Ignore outdated message.
|
|
if !edge2Timestamp.Before(msg.LastUpdate) {
|
|
return newErrf(ErrOutdated, "Ignoring "+
|
|
"outdated update (flags=%v|%v) for "+
|
|
"known chan_id=%v", msg.MessageFlags,
|
|
msg.ChannelFlags, msg.ChannelID)
|
|
}
|
|
}
|
|
|
|
// Now that we know this isn't a stale update, we'll apply the
|
|
// new edge policy to the proper directional edge within the
|
|
// channel graph.
|
|
if err = r.cfg.Graph.UpdateEdgePolicy(msg); err != nil {
|
|
err := errors.Errorf("unable to add channel: %v", err)
|
|
log.Error(err)
|
|
return err
|
|
}
|
|
|
|
invalidateCache = true
|
|
log.Tracef("New channel update applied: %v",
|
|
newLogClosure(func() string { return spew.Sdump(msg) }))
|
|
|
|
default:
|
|
return errors.Errorf("wrong routing update message type")
|
|
}
|
|
|
|
// If we've received a channel update, then invalidate the route cache
|
|
// as channels within the graph have closed, which may affect our
|
|
// choice of the KSP's for a particular routeTuple.
|
|
if invalidateCache {
|
|
r.routeCacheMtx.Lock()
|
|
r.routeCache = make(map[routeTuple][]*Route)
|
|
r.routeCacheMtx.Unlock()
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
// fetchChanPoint retrieves the original outpoint which is encoded within the
|
|
// channelID. This method also return the public key script for the target
|
|
// transaction.
|
|
//
|
|
// TODO(roasbeef): replace with call to GetBlockTransaction? (would allow to
|
|
// later use getblocktxn)
|
|
func (r *ChannelRouter) fetchChanPoint(
|
|
chanID *lnwire.ShortChannelID) (*wire.OutPoint, *wire.TxOut, error) {
|
|
|
|
// First fetch the block hash by the block number encoded, then use
|
|
// that hash to fetch the block itself.
|
|
blockNum := int64(chanID.BlockHeight)
|
|
blockHash, err := r.cfg.Chain.GetBlockHash(blockNum)
|
|
if err != nil {
|
|
return nil, nil, err
|
|
}
|
|
fundingBlock, err := r.cfg.Chain.GetBlock(blockHash)
|
|
if err != nil {
|
|
return nil, nil, err
|
|
}
|
|
|
|
// As a sanity check, ensure that the advertised transaction index is
|
|
// within the bounds of the total number of transactions within a
|
|
// block.
|
|
numTxns := uint32(len(fundingBlock.Transactions))
|
|
if chanID.TxIndex > numTxns-1 {
|
|
return nil, nil, fmt.Errorf("tx_index=#%v is out of range "+
|
|
"(max_index=%v), network_chan_id=%v\n", chanID.TxIndex,
|
|
numTxns-1, spew.Sdump(chanID))
|
|
}
|
|
|
|
// Finally once we have the block itself, we seek to the targeted
|
|
// transaction index to obtain the funding output and txout.
|
|
fundingTx := fundingBlock.Transactions[chanID.TxIndex]
|
|
outPoint := &wire.OutPoint{
|
|
Hash: fundingTx.TxHash(),
|
|
Index: uint32(chanID.TxPosition),
|
|
}
|
|
txOut := fundingTx.TxOut[chanID.TxPosition]
|
|
|
|
return outPoint, txOut, nil
|
|
}
|
|
|
|
// routingMsg couples a routing related routing topology update to the
|
|
// error channel.
|
|
type routingMsg struct {
|
|
msg interface{}
|
|
err chan error
|
|
}
|
|
|
|
// pathsToFeeSortedRoutes takes a set of paths, and returns a corresponding set
|
|
// of routes. A route differs from a path in that it has full time-lock and
|
|
// fee information attached. The set of routes returned may be less than the
|
|
// initial set of paths as it's possible we drop a route if it can't handle the
|
|
// total payment flow after fees are calculated.
|
|
func pathsToFeeSortedRoutes(source Vertex, paths [][]*channeldb.ChannelEdgePolicy,
|
|
finalCLTVDelta uint16, amt lnwire.MilliSatoshi,
|
|
currentHeight uint32) ([]*Route, error) {
|
|
|
|
validRoutes := make([]*Route, 0, len(paths))
|
|
for _, path := range paths {
|
|
// Attempt to make the path into a route. We snip off the first
|
|
// hop in the path as it contains a "self-hop" that is inserted
|
|
// by our KSP algorithm.
|
|
route, err := newRoute(
|
|
amt, source, path[1:], currentHeight, finalCLTVDelta,
|
|
)
|
|
if err != nil {
|
|
// TODO(roasbeef): report straw breaking edge?
|
|
continue
|
|
}
|
|
|
|
// If the path as enough total flow to support the computed
|
|
// route, then we'll add it to our set of valid routes.
|
|
validRoutes = append(validRoutes, route)
|
|
}
|
|
|
|
// If all our perspective routes were eliminating during the transition
|
|
// from path to route, then we'll return an error to the caller
|
|
if len(validRoutes) == 0 {
|
|
return nil, newErr(ErrNoPathFound, "unable to find a path to "+
|
|
"destination")
|
|
}
|
|
|
|
// Finally, we'll sort the set of validate routes to optimize for
|
|
// lowest total fees, using the required time-lock within the route as
|
|
// a tie-breaker.
|
|
sort.Slice(validRoutes, func(i, j int) bool {
|
|
// To make this decision we first check if the total fees
|
|
// required for both routes are equal. If so, then we'll let
|
|
// the total time lock be the tie breaker. Otherwise, we'll put
|
|
// the route with the lowest total fees first.
|
|
if validRoutes[i].TotalFees == validRoutes[j].TotalFees {
|
|
timeLockI := validRoutes[i].TotalTimeLock
|
|
timeLockJ := validRoutes[j].TotalTimeLock
|
|
return timeLockI < timeLockJ
|
|
}
|
|
|
|
return validRoutes[i].TotalFees < validRoutes[j].TotalFees
|
|
})
|
|
|
|
return validRoutes, nil
|
|
}
|
|
|
|
// FindRoutes attempts to query the ChannelRouter for a bounded number
|
|
// available paths to a particular target destination which is able to send
|
|
// `amt` after factoring in channel capacities and cumulative fees along each
|
|
// route. To `numPaths eligible paths, we use a modified version of
|
|
// Yen's algorithm which itself uses a modified version of Dijkstra's algorithm
|
|
// within its inner loop. Once we have a set of candidate routes, we calculate
|
|
// the required fee and time lock values running backwards along the route. The
|
|
// route that will be ranked the highest is the one with the lowest cumulative
|
|
// fee along the route.
|
|
func (r *ChannelRouter) FindRoutes(source, target Vertex,
|
|
amt lnwire.MilliSatoshi, restrictions *RestrictParams, numPaths uint32,
|
|
finalExpiry ...uint16) ([]*Route, error) {
|
|
|
|
var finalCLTVDelta uint16
|
|
if len(finalExpiry) == 0 {
|
|
finalCLTVDelta = zpay32.DefaultFinalCLTVDelta
|
|
} else {
|
|
finalCLTVDelta = finalExpiry[0]
|
|
}
|
|
|
|
log.Debugf("Searching for path to %x, sending %v", target, amt)
|
|
|
|
// Before attempting to perform a series of graph traversals to find the
|
|
// k-shortest paths to the destination, we'll first consult our path
|
|
// cache
|
|
//
|
|
// TODO: Route cache should store all request parameters instead of just
|
|
// amt and target. Currently false positives are returned if just the
|
|
// restrictions (fee limit, ignore lists) or finalExpiry are different.
|
|
rt := newRouteTuple(amt, target[:])
|
|
r.routeCacheMtx.RLock()
|
|
routes, ok := r.routeCache[rt]
|
|
r.routeCacheMtx.RUnlock()
|
|
|
|
// If we already have a cached route, and it contains at least the
|
|
// number of paths requested, then we'll return it directly as there's
|
|
// no need to repeat the computation.
|
|
if ok && uint32(len(routes)) >= numPaths {
|
|
return routes, nil
|
|
}
|
|
|
|
// If we don't have a set of routes cached, we'll query the graph for a
|
|
// set of potential routes to the destination node that can support our
|
|
// payment amount. If no such routes can be found then an error will be
|
|
// returned.
|
|
|
|
// We can short circuit the routing by opportunistically checking to
|
|
// see if the target vertex event exists in the current graph.
|
|
if _, exists, err := r.cfg.Graph.HasLightningNode(target); err != nil {
|
|
return nil, err
|
|
} else if !exists {
|
|
log.Debugf("Target %x is not in known graph", target)
|
|
return nil, newErrf(ErrTargetNotInNetwork, "target not found")
|
|
}
|
|
|
|
// We'll also fetch the current block height so we can properly
|
|
// calculate the required HTLC time locks within the route.
|
|
_, currentHeight, err := r.cfg.Chain.GetBestBlock()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
// Before we open the db transaction below, we'll attempt to obtain a
|
|
// set of bandwidth hints that can help us eliminate certain routes
|
|
// early on in the path finding process.
|
|
bandwidthHints, err := generateBandwidthHints(
|
|
r.selfNode, r.cfg.QueryBandwidth,
|
|
)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
tx, err := r.cfg.Graph.Database().Begin(false)
|
|
if err != nil {
|
|
tx.Rollback()
|
|
return nil, err
|
|
}
|
|
|
|
// Now that we know the destination is reachable within the graph,
|
|
// we'll execute our KSP algorithm to find the k-shortest paths from
|
|
// our source to the destination.
|
|
shortestPaths, err := findPaths(
|
|
tx, r.cfg.Graph, source, target, amt, restrictions,
|
|
numPaths, bandwidthHints,
|
|
)
|
|
if err != nil {
|
|
tx.Rollback()
|
|
return nil, err
|
|
}
|
|
|
|
tx.Rollback()
|
|
|
|
// Now that we have a set of paths, we'll need to turn them into
|
|
// *routes* by computing the required time-lock and fee information for
|
|
// each path. During this process, some paths may be discarded if they
|
|
// aren't able to support the total satoshis flow once fees have been
|
|
// factored in.
|
|
sourceVertex := Vertex(r.selfNode.PubKeyBytes)
|
|
validRoutes, err := pathsToFeeSortedRoutes(
|
|
sourceVertex, shortestPaths, finalCLTVDelta, amt,
|
|
uint32(currentHeight),
|
|
)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
go log.Tracef("Obtained %v paths sending %v to %x: %v", len(validRoutes),
|
|
amt, target, newLogClosure(func() string {
|
|
return spew.Sdump(validRoutes)
|
|
}),
|
|
)
|
|
|
|
// Populate the cache with this set of fresh routes so we can reuse
|
|
// them in the future.
|
|
r.routeCacheMtx.Lock()
|
|
r.routeCache[rt] = validRoutes
|
|
r.routeCacheMtx.Unlock()
|
|
|
|
return validRoutes, nil
|
|
}
|
|
|
|
// generateSphinxPacket generates then encodes a sphinx packet which encodes
|
|
// the onion route specified by the passed layer 3 route. The blob returned
|
|
// from this function can immediately be included within an HTLC add packet to
|
|
// be sent to the first hop within the route.
|
|
func generateSphinxPacket(route *Route, paymentHash []byte) ([]byte,
|
|
*sphinx.Circuit, error) {
|
|
|
|
// As a sanity check, we'll ensure that the set of hops has been
|
|
// properly filled in, otherwise, we won't actually be able to
|
|
// construct a route.
|
|
if len(route.Hops) == 0 {
|
|
return nil, nil, ErrNoRouteHopsProvided
|
|
}
|
|
|
|
// First obtain all the public keys along the route which are contained
|
|
// in each hop.
|
|
nodes := make([]*btcec.PublicKey, len(route.Hops))
|
|
for i, hop := range route.Hops {
|
|
pub, err := btcec.ParsePubKey(hop.PubKeyBytes[:],
|
|
btcec.S256())
|
|
if err != nil {
|
|
return nil, nil, err
|
|
}
|
|
|
|
nodes[i] = pub
|
|
}
|
|
|
|
// Next we generate the per-hop payload which gives each node within
|
|
// the route the necessary information (fees, CLTV value, etc) to
|
|
// properly forward the payment.
|
|
hopPayloads := route.ToHopPayloads()
|
|
|
|
log.Tracef("Constructed per-hop payloads for payment_hash=%x: %v",
|
|
paymentHash[:], newLogClosure(func() string {
|
|
return spew.Sdump(hopPayloads)
|
|
}),
|
|
)
|
|
|
|
sessionKey, err := btcec.NewPrivateKey(btcec.S256())
|
|
if err != nil {
|
|
return nil, nil, err
|
|
}
|
|
|
|
// Next generate the onion routing packet which allows us to perform
|
|
// privacy preserving source routing across the network.
|
|
sphinxPacket, err := sphinx.NewOnionPacket(
|
|
nodes, sessionKey, hopPayloads, paymentHash,
|
|
)
|
|
if err != nil {
|
|
return nil, nil, err
|
|
}
|
|
|
|
// Finally, encode Sphinx packet using its wire representation to be
|
|
// included within the HTLC add packet.
|
|
var onionBlob bytes.Buffer
|
|
if err := sphinxPacket.Encode(&onionBlob); err != nil {
|
|
return nil, nil, err
|
|
}
|
|
|
|
log.Tracef("Generated sphinx packet: %v",
|
|
newLogClosure(func() string {
|
|
// We unset the internal curve here in order to keep
|
|
// the logs from getting noisy.
|
|
sphinxPacket.EphemeralKey.Curve = nil
|
|
return spew.Sdump(sphinxPacket)
|
|
}),
|
|
)
|
|
|
|
return onionBlob.Bytes(), &sphinx.Circuit{
|
|
SessionKey: sessionKey,
|
|
PaymentPath: nodes,
|
|
}, nil
|
|
}
|
|
|
|
// LightningPayment describes a payment to be sent through the network to the
|
|
// final destination.
|
|
type LightningPayment struct {
|
|
// Target is the node in which the payment should be routed towards.
|
|
Target Vertex
|
|
|
|
// Amount is the value of the payment to send through the network in
|
|
// milli-satoshis.
|
|
Amount lnwire.MilliSatoshi
|
|
|
|
// FeeLimit is the maximum fee in millisatoshis that the payment should
|
|
// accept when sending it through the network. The payment will fail
|
|
// if there isn't a route with lower fees than this limit.
|
|
FeeLimit lnwire.MilliSatoshi
|
|
|
|
// CltvLimit is the maximum time lock that is allowed for attempts to
|
|
// complete this payment.
|
|
CltvLimit *uint32
|
|
|
|
// PaymentHash is the r-hash value to use within the HTLC extended to
|
|
// the first hop.
|
|
PaymentHash [32]byte
|
|
|
|
// FinalCLTVDelta is the CTLV expiry delta to use for the _final_ hop
|
|
// in the route. This means that the final hop will have a CLTV delta
|
|
// of at least: currentHeight + FinalCLTVDelta. If this value is
|
|
// unspecified, then a default value of DefaultFinalCLTVDelta will be
|
|
// used.
|
|
FinalCLTVDelta *uint16
|
|
|
|
// PayAttemptTimeout is a timeout value that we'll use to determine
|
|
// when we should should abandon the payment attempt after consecutive
|
|
// payment failure. This prevents us from attempting to send a payment
|
|
// indefinitely.
|
|
PayAttemptTimeout time.Duration
|
|
|
|
// RouteHints represents the different routing hints that can be used to
|
|
// assist a payment in reaching its destination successfully. These
|
|
// hints will act as intermediate hops along the route.
|
|
//
|
|
// NOTE: This is optional unless required by the payment. When providing
|
|
// multiple routes, ensure the hop hints within each route are chained
|
|
// together and sorted in forward order in order to reach the
|
|
// destination successfully.
|
|
RouteHints [][]zpay32.HopHint
|
|
|
|
// OutgoingChannelID is the channel that needs to be taken to the first
|
|
// hop. If nil, any channel may be used.
|
|
OutgoingChannelID *uint64
|
|
|
|
// TODO(roasbeef): add e2e message?
|
|
}
|
|
|
|
// SendPayment attempts to send a payment as described within the passed
|
|
// LightningPayment. This function is blocking and will return either: when the
|
|
// payment is successful, or all candidates routes have been attempted and
|
|
// resulted in a failed payment. If the payment succeeds, then a non-nil Route
|
|
// will be returned which describes the path the successful payment traversed
|
|
// within the network to reach the destination. Additionally, the payment
|
|
// preimage will also be returned.
|
|
func (r *ChannelRouter) SendPayment(payment *LightningPayment) ([32]byte, *Route, error) {
|
|
// Before starting the HTLC routing attempt, we'll create a fresh
|
|
// payment session which will report our errors back to mission
|
|
// control.
|
|
paySession, err := r.missionControl.NewPaymentSession(
|
|
payment.RouteHints, payment.Target,
|
|
)
|
|
if err != nil {
|
|
return [32]byte{}, nil, err
|
|
}
|
|
|
|
return r.sendPayment(payment, paySession)
|
|
}
|
|
|
|
// SendToRoute attempts to send a payment as described within the passed
|
|
// LightningPayment through the provided routes. This function is blocking
|
|
// and will return either: when the payment is successful, or all routes
|
|
// have been attempted and resulted in a failed payment. If the payment
|
|
// succeeds, then a non-nil Route will be returned which describes the
|
|
// path the successful payment traversed within the network to reach the
|
|
// destination. Additionally, the payment preimage will also be returned.
|
|
func (r *ChannelRouter) SendToRoute(routes []*Route,
|
|
payment *LightningPayment) ([32]byte, *Route, error) {
|
|
|
|
paySession := r.missionControl.NewPaymentSessionFromRoutes(
|
|
routes,
|
|
)
|
|
|
|
return r.sendPayment(payment, paySession)
|
|
}
|
|
|
|
// sendPayment attempts to send a payment as described within the passed
|
|
// LightningPayment. This function is blocking and will return either: when the
|
|
// payment is successful, or all candidates routes have been attempted and
|
|
// resulted in a failed payment. If the payment succeeds, then a non-nil Route
|
|
// will be returned which describes the path the successful payment traversed
|
|
// within the network to reach the destination. Additionally, the payment
|
|
// preimage will also be returned.
|
|
func (r *ChannelRouter) sendPayment(payment *LightningPayment,
|
|
paySession *paymentSession) ([32]byte, *Route, error) {
|
|
|
|
log.Tracef("Dispatching route for lightning payment: %v",
|
|
newLogClosure(func() string {
|
|
for _, routeHint := range payment.RouteHints {
|
|
for _, hopHint := range routeHint {
|
|
hopHint.NodeID.Curve = nil
|
|
}
|
|
}
|
|
return spew.Sdump(payment)
|
|
}),
|
|
)
|
|
|
|
// We'll also fetch the current block height so we can properly
|
|
// calculate the required HTLC time locks within the route.
|
|
_, currentHeight, err := r.cfg.Chain.GetBestBlock()
|
|
if err != nil {
|
|
return [32]byte{}, nil, err
|
|
}
|
|
|
|
var finalCLTVDelta uint16
|
|
if payment.FinalCLTVDelta == nil {
|
|
finalCLTVDelta = zpay32.DefaultFinalCLTVDelta
|
|
} else {
|
|
finalCLTVDelta = *payment.FinalCLTVDelta
|
|
}
|
|
|
|
var payAttemptTimeout time.Duration
|
|
if payment.PayAttemptTimeout == time.Duration(0) {
|
|
payAttemptTimeout = defaultPayAttemptTimeout
|
|
} else {
|
|
payAttemptTimeout = payment.PayAttemptTimeout
|
|
}
|
|
|
|
timeoutChan := time.After(payAttemptTimeout)
|
|
|
|
// We'll continue until either our payment succeeds, or we encounter a
|
|
// critical error during path finding.
|
|
var lastError error
|
|
for {
|
|
// Before we attempt this next payment, we'll check to see if
|
|
// either we've gone past the payment attempt timeout, or the
|
|
// router is exiting. In either case, we'll stop this payment
|
|
// attempt short.
|
|
select {
|
|
case <-timeoutChan:
|
|
errStr := fmt.Sprintf("payment attempt not completed "+
|
|
"before timeout of %v", payAttemptTimeout)
|
|
|
|
return [32]byte{}, nil, newErr(
|
|
ErrPaymentAttemptTimeout, errStr,
|
|
)
|
|
|
|
case <-r.quit:
|
|
return [32]byte{}, nil, fmt.Errorf("router shutting down")
|
|
|
|
default:
|
|
// Fall through if we haven't hit our time limit, or
|
|
// are expiring.
|
|
}
|
|
|
|
route, err := paySession.RequestRoute(
|
|
payment, uint32(currentHeight), finalCLTVDelta,
|
|
)
|
|
if err != nil {
|
|
// If we're unable to successfully make a payment using
|
|
// any of the routes we've found, then return an error.
|
|
if lastError != nil {
|
|
return [32]byte{}, nil, fmt.Errorf("unable to "+
|
|
"route payment to destination: %v",
|
|
lastError)
|
|
}
|
|
|
|
return [32]byte{}, nil, err
|
|
}
|
|
|
|
// Send payment attempt. It will return a final boolean
|
|
// indicating if more attempts are needed.
|
|
preimage, final, err := r.sendPaymentAttempt(
|
|
paySession, route, payment.PaymentHash,
|
|
)
|
|
if final {
|
|
return preimage, route, err
|
|
}
|
|
|
|
lastError = err
|
|
}
|
|
}
|
|
|
|
// sendPaymentAttempt tries to send the payment via the specified route. If
|
|
// successful, it returns the obtained preimage. If an error occurs, the last
|
|
// bool parameter indicates whether this is a final outcome or more attempts
|
|
// should be made.
|
|
func (r *ChannelRouter) sendPaymentAttempt(paySession *paymentSession,
|
|
route *Route, paymentHash [32]byte) ([32]byte, bool, error) {
|
|
|
|
log.Tracef("Attempting to send payment %x, using route: %v",
|
|
paymentHash, newLogClosure(func() string {
|
|
return spew.Sdump(route)
|
|
}),
|
|
)
|
|
|
|
preimage, err := r.sendToSwitch(route, paymentHash)
|
|
if err == nil {
|
|
return preimage, true, nil
|
|
}
|
|
|
|
log.Errorf("Attempt to send payment %x failed: %v",
|
|
paymentHash, err)
|
|
|
|
finalOutcome := r.processSendError(paySession, route, err)
|
|
|
|
return [32]byte{}, finalOutcome, err
|
|
}
|
|
|
|
// sendToSwitch sends a payment along the specified route and returns the
|
|
// obtained preimage.
|
|
func (r *ChannelRouter) sendToSwitch(route *Route, paymentHash [32]byte) (
|
|
[32]byte, error) {
|
|
|
|
// Generate the raw encoded sphinx packet to be included along
|
|
// with the htlcAdd message that we send directly to the
|
|
// switch.
|
|
onionBlob, circuit, err := generateSphinxPacket(
|
|
route, paymentHash[:],
|
|
)
|
|
if err != nil {
|
|
return [32]byte{}, err
|
|
}
|
|
|
|
// Craft an HTLC packet to send to the layer 2 switch. The
|
|
// metadata within this packet will be used to route the
|
|
// payment through the network, starting with the first-hop.
|
|
htlcAdd := &lnwire.UpdateAddHTLC{
|
|
Amount: route.TotalAmount,
|
|
Expiry: route.TotalTimeLock,
|
|
PaymentHash: paymentHash,
|
|
}
|
|
copy(htlcAdd.OnionBlob[:], onionBlob)
|
|
|
|
// Attempt to send this payment through the network to complete
|
|
// the payment. If this attempt fails, then we'll continue on
|
|
// to the next available route.
|
|
firstHop := lnwire.NewShortChanIDFromInt(
|
|
route.Hops[0].ChannelID,
|
|
)
|
|
return r.cfg.SendToSwitch(
|
|
firstHop, htlcAdd, circuit,
|
|
)
|
|
}
|
|
|
|
// processSendError analyzes the error for the payment attempt received from the
|
|
// switch and updates mission control and/or channel policies. Depending on the
|
|
// error type, this error is either the final outcome of the payment or we need
|
|
// to continue with an alternative route. This is indicated by the boolean
|
|
// return value.
|
|
func (r *ChannelRouter) processSendError(paySession *paymentSession,
|
|
route *Route, err error) bool {
|
|
|
|
fErr, ok := err.(*htlcswitch.ForwardingError)
|
|
if !ok {
|
|
return true
|
|
}
|
|
|
|
errSource := fErr.ErrorSource
|
|
errVertex := NewVertex(errSource)
|
|
|
|
log.Tracef("node=%x reported failure when sending htlc", errVertex)
|
|
|
|
// Always determine chan id ourselves, because a channel
|
|
// update with id may not be available.
|
|
failedEdge, err := getFailedEdge(route, errVertex)
|
|
if err != nil {
|
|
return true
|
|
}
|
|
|
|
// processChannelUpdateAndRetry is a closure that
|
|
// handles a failure message containing a channel
|
|
// update. This function always tries to apply the
|
|
// channel update and passes on the result to the
|
|
// payment session to adjust its view on the reliability
|
|
// of the network.
|
|
//
|
|
// As channel id, the locally determined channel id is
|
|
// used. It does not rely on the channel id that is part
|
|
// of the channel update message, because the remote
|
|
// node may lie to us or the update may be corrupt.
|
|
processChannelUpdateAndRetry := func(
|
|
update *lnwire.ChannelUpdate,
|
|
pubKey *btcec.PublicKey) {
|
|
|
|
// Try to apply the channel update.
|
|
updateOk := r.applyChannelUpdate(update, pubKey)
|
|
|
|
// If the update could not be applied, prune the
|
|
// edge. There is no reason to continue trying
|
|
// this channel.
|
|
//
|
|
// TODO: Could even prune the node completely?
|
|
// Or is there a valid reason for the channel
|
|
// update to fail?
|
|
if !updateOk {
|
|
paySession.ReportEdgeFailure(
|
|
failedEdge,
|
|
)
|
|
}
|
|
|
|
paySession.ReportEdgePolicyFailure(
|
|
NewVertex(errSource), failedEdge,
|
|
)
|
|
}
|
|
|
|
switch onionErr := fErr.FailureMessage.(type) {
|
|
|
|
// If the end destination didn't know the payment
|
|
// hash or we sent the wrong payment amount to the
|
|
// destination, then we'll terminate immediately.
|
|
case *lnwire.FailUnknownPaymentHash:
|
|
return true
|
|
|
|
// If we sent the wrong amount to the destination, then
|
|
// we'll exit early.
|
|
case *lnwire.FailIncorrectPaymentAmount:
|
|
return true
|
|
|
|
// If the time-lock that was extended to the final node
|
|
// was incorrect, then we can't proceed.
|
|
case *lnwire.FailFinalIncorrectCltvExpiry:
|
|
return true
|
|
|
|
// If we crafted an invalid onion payload for the final
|
|
// node, then we'll exit early.
|
|
case *lnwire.FailFinalIncorrectHtlcAmount:
|
|
return true
|
|
|
|
// Similarly, if the HTLC expiry that we extended to
|
|
// the final hop expires too soon, then will fail the
|
|
// payment.
|
|
//
|
|
// TODO(roasbeef): can happen to to race condition, try
|
|
// again with recent block height
|
|
case *lnwire.FailFinalExpiryTooSoon:
|
|
return true
|
|
|
|
// If we erroneously attempted to cross a chain border,
|
|
// then we'll cancel the payment.
|
|
case *lnwire.FailInvalidRealm:
|
|
return true
|
|
|
|
// If we get a notice that the expiry was too soon for
|
|
// an intermediate node, then we'll prune out the node
|
|
// that sent us this error, as it doesn't now what the
|
|
// correct block height is.
|
|
case *lnwire.FailExpiryTooSoon:
|
|
r.applyChannelUpdate(&onionErr.Update, errSource)
|
|
paySession.ReportVertexFailure(errVertex)
|
|
return false
|
|
|
|
// If we hit an instance of onion payload corruption or
|
|
// an invalid version, then we'll exit early as this
|
|
// shouldn't happen in the typical case.
|
|
case *lnwire.FailInvalidOnionVersion:
|
|
return true
|
|
case *lnwire.FailInvalidOnionHmac:
|
|
return true
|
|
case *lnwire.FailInvalidOnionKey:
|
|
return true
|
|
|
|
// If we get a failure due to violating the minimum
|
|
// amount, we'll apply the new minimum amount and retry
|
|
// routing.
|
|
case *lnwire.FailAmountBelowMinimum:
|
|
processChannelUpdateAndRetry(
|
|
&onionErr.Update, errSource,
|
|
)
|
|
return false
|
|
|
|
// If we get a failure due to a fee, we'll apply the
|
|
// new fee update, and retry our attempt using the
|
|
// newly updated fees.
|
|
case *lnwire.FailFeeInsufficient:
|
|
processChannelUpdateAndRetry(
|
|
&onionErr.Update, errSource,
|
|
)
|
|
return false
|
|
|
|
// If we get the failure for an intermediate node that
|
|
// disagrees with our time lock values, then we'll
|
|
// apply the new delta value and try it once more.
|
|
case *lnwire.FailIncorrectCltvExpiry:
|
|
processChannelUpdateAndRetry(
|
|
&onionErr.Update, errSource,
|
|
)
|
|
return false
|
|
|
|
// The outgoing channel that this node was meant to
|
|
// forward one is currently disabled, so we'll apply
|
|
// the update and continue.
|
|
case *lnwire.FailChannelDisabled:
|
|
r.applyChannelUpdate(&onionErr.Update, errSource)
|
|
paySession.ReportEdgeFailure(failedEdge)
|
|
return false
|
|
|
|
// It's likely that the outgoing channel didn't have
|
|
// sufficient capacity, so we'll prune this edge for
|
|
// now, and continue onwards with our path finding.
|
|
case *lnwire.FailTemporaryChannelFailure:
|
|
r.applyChannelUpdate(onionErr.Update, errSource)
|
|
paySession.ReportEdgeFailure(failedEdge)
|
|
return false
|
|
|
|
// If the send fail due to a node not having the
|
|
// required features, then we'll note this error and
|
|
// continue.
|
|
case *lnwire.FailRequiredNodeFeatureMissing:
|
|
paySession.ReportVertexFailure(errVertex)
|
|
return false
|
|
|
|
// If the send fail due to a node not having the
|
|
// required features, then we'll note this error and
|
|
// continue.
|
|
case *lnwire.FailRequiredChannelFeatureMissing:
|
|
paySession.ReportVertexFailure(errVertex)
|
|
return false
|
|
|
|
// If the next hop in the route wasn't known or
|
|
// offline, we'll only the channel which we attempted
|
|
// to route over. This is conservative, and it can
|
|
// handle faulty channels between nodes properly.
|
|
// Additionally, this guards against routing nodes
|
|
// returning errors in order to attempt to black list
|
|
// another node.
|
|
case *lnwire.FailUnknownNextPeer:
|
|
paySession.ReportEdgeFailure(failedEdge)
|
|
return false
|
|
|
|
// If the node wasn't able to forward for which ever
|
|
// reason, then we'll note this and continue with the
|
|
// routes.
|
|
case *lnwire.FailTemporaryNodeFailure:
|
|
paySession.ReportVertexFailure(errVertex)
|
|
return false
|
|
|
|
case *lnwire.FailPermanentNodeFailure:
|
|
paySession.ReportVertexFailure(errVertex)
|
|
return false
|
|
|
|
// If we crafted a route that contains a too long time
|
|
// lock for an intermediate node, we'll prune the node.
|
|
// As there currently is no way of knowing that node's
|
|
// maximum acceptable cltv, we cannot take this
|
|
// constraint into account during routing.
|
|
//
|
|
// TODO(joostjager): Record the rejected cltv and use
|
|
// that as a hint during future path finding through
|
|
// that node.
|
|
case *lnwire.FailExpiryTooFar:
|
|
paySession.ReportVertexFailure(errVertex)
|
|
return false
|
|
|
|
// If we get a permanent channel or node failure, then
|
|
// we'll prune the channel in both directions and
|
|
// continue with the rest of the routes.
|
|
case *lnwire.FailPermanentChannelFailure:
|
|
paySession.ReportEdgeFailure(&EdgeLocator{
|
|
ChannelID: failedEdge.ChannelID,
|
|
Direction: 0,
|
|
})
|
|
paySession.ReportEdgeFailure(&EdgeLocator{
|
|
ChannelID: failedEdge.ChannelID,
|
|
Direction: 1,
|
|
})
|
|
return false
|
|
|
|
default:
|
|
return true
|
|
}
|
|
}
|
|
|
|
// getFailedEdge tries to locate the failing channel given a route and the
|
|
// pubkey of the node that sent the error. It will assume that the error is
|
|
// associated with the outgoing channel of the error node.
|
|
func getFailedEdge(route *Route, errSource Vertex) (
|
|
*EdgeLocator, error) {
|
|
|
|
hopCount := len(route.Hops)
|
|
fromNode := route.SourcePubKey
|
|
for i, hop := range route.Hops {
|
|
toNode := hop.PubKeyBytes
|
|
|
|
// Determine if we have a failure from the final hop.
|
|
//
|
|
// TODO(joostjager): In this case, certain types of errors are
|
|
// not expected. For example FailUnknownNextPeer. This could be
|
|
// a reason to prune the node?
|
|
finalHopFailing := i == hopCount-1 && errSource == toNode
|
|
|
|
// As this error indicates that the target channel was unable to
|
|
// carry this HTLC (for w/e reason), we'll return the _outgoing_
|
|
// channel that the source of the error was meant to pass the
|
|
// HTLC along to.
|
|
//
|
|
// If the errSource is the final hop, we assume that the failing
|
|
// channel is the incoming channel.
|
|
if errSource == fromNode || finalHopFailing {
|
|
return newEdgeLocatorByPubkeys(
|
|
hop.ChannelID,
|
|
&fromNode,
|
|
&toNode,
|
|
), nil
|
|
}
|
|
|
|
fromNode = toNode
|
|
}
|
|
|
|
return nil, fmt.Errorf("cannot find error source node in route")
|
|
}
|
|
|
|
// applyChannelUpdate validates a channel update and if valid, applies it to the
|
|
// database. It returns a bool indicating whether the updates was successful.
|
|
func (r *ChannelRouter) applyChannelUpdate(msg *lnwire.ChannelUpdate,
|
|
pubKey *btcec.PublicKey) bool {
|
|
// If we get passed a nil channel update (as it's optional with some
|
|
// onion errors), then we'll exit early with a success result.
|
|
if msg == nil {
|
|
return true
|
|
}
|
|
|
|
ch, _, _, err := r.GetChannelByID(msg.ShortChannelID)
|
|
if err != nil {
|
|
log.Errorf("Unable to retrieve channel by id: %v", err)
|
|
return false
|
|
}
|
|
|
|
if err := ValidateChannelUpdateAnn(pubKey, ch.Capacity, msg); err != nil {
|
|
log.Errorf("Unable to validate channel update: %v", err)
|
|
return false
|
|
}
|
|
|
|
err = r.UpdateEdge(&channeldb.ChannelEdgePolicy{
|
|
SigBytes: msg.Signature.ToSignatureBytes(),
|
|
ChannelID: msg.ShortChannelID.ToUint64(),
|
|
LastUpdate: time.Unix(int64(msg.Timestamp), 0),
|
|
MessageFlags: msg.MessageFlags,
|
|
ChannelFlags: msg.ChannelFlags,
|
|
TimeLockDelta: msg.TimeLockDelta,
|
|
MinHTLC: msg.HtlcMinimumMsat,
|
|
MaxHTLC: msg.HtlcMaximumMsat,
|
|
FeeBaseMSat: lnwire.MilliSatoshi(msg.BaseFee),
|
|
FeeProportionalMillionths: lnwire.MilliSatoshi(msg.FeeRate),
|
|
})
|
|
if err != nil && !IsError(err, ErrIgnored, ErrOutdated) {
|
|
log.Errorf("Unable to apply channel update: %v", err)
|
|
return false
|
|
}
|
|
|
|
return true
|
|
}
|
|
|
|
// AddNode is used to add information about a node to the router database. If
|
|
// the node with this pubkey is not present in an existing channel, it will
|
|
// be ignored.
|
|
//
|
|
// NOTE: This method is part of the ChannelGraphSource interface.
|
|
func (r *ChannelRouter) AddNode(node *channeldb.LightningNode) error {
|
|
rMsg := &routingMsg{
|
|
msg: node,
|
|
err: make(chan error, 1),
|
|
}
|
|
|
|
select {
|
|
case r.networkUpdates <- rMsg:
|
|
select {
|
|
case err := <-rMsg.err:
|
|
return err
|
|
case <-r.quit:
|
|
return errors.New("router has been shut down")
|
|
}
|
|
case <-r.quit:
|
|
return errors.New("router has been shut down")
|
|
}
|
|
}
|
|
|
|
// AddEdge is used to add edge/channel to the topology of the router, after all
|
|
// information about channel will be gathered this edge/channel might be used
|
|
// in construction of payment path.
|
|
//
|
|
// NOTE: This method is part of the ChannelGraphSource interface.
|
|
func (r *ChannelRouter) AddEdge(edge *channeldb.ChannelEdgeInfo) error {
|
|
rMsg := &routingMsg{
|
|
msg: edge,
|
|
err: make(chan error, 1),
|
|
}
|
|
|
|
select {
|
|
case r.networkUpdates <- rMsg:
|
|
select {
|
|
case err := <-rMsg.err:
|
|
return err
|
|
case <-r.quit:
|
|
return errors.New("router has been shut down")
|
|
}
|
|
case <-r.quit:
|
|
return errors.New("router has been shut down")
|
|
}
|
|
}
|
|
|
|
// UpdateEdge is used to update edge information, without this message edge
|
|
// considered as not fully constructed.
|
|
//
|
|
// NOTE: This method is part of the ChannelGraphSource interface.
|
|
func (r *ChannelRouter) UpdateEdge(update *channeldb.ChannelEdgePolicy) error {
|
|
rMsg := &routingMsg{
|
|
msg: update,
|
|
err: make(chan error, 1),
|
|
}
|
|
|
|
select {
|
|
case r.networkUpdates <- rMsg:
|
|
select {
|
|
case err := <-rMsg.err:
|
|
return err
|
|
case <-r.quit:
|
|
return errors.New("router has been shut down")
|
|
}
|
|
case <-r.quit:
|
|
return errors.New("router has been shut down")
|
|
}
|
|
}
|
|
|
|
// CurrentBlockHeight returns the block height from POV of the router subsystem.
|
|
//
|
|
// NOTE: This method is part of the ChannelGraphSource interface.
|
|
func (r *ChannelRouter) CurrentBlockHeight() (uint32, error) {
|
|
_, height, err := r.cfg.Chain.GetBestBlock()
|
|
return uint32(height), err
|
|
}
|
|
|
|
// GetChannelByID return the channel by the channel id.
|
|
//
|
|
// NOTE: This method is part of the ChannelGraphSource interface.
|
|
func (r *ChannelRouter) GetChannelByID(chanID lnwire.ShortChannelID) (
|
|
*channeldb.ChannelEdgeInfo,
|
|
*channeldb.ChannelEdgePolicy,
|
|
*channeldb.ChannelEdgePolicy, error) {
|
|
|
|
return r.cfg.Graph.FetchChannelEdgesByID(chanID.ToUint64())
|
|
}
|
|
|
|
// FetchLightningNode attempts to look up a target node by its identity public
|
|
// key. channeldb.ErrGraphNodeNotFound is returned if the node doesn't exist
|
|
// within the graph.
|
|
//
|
|
// NOTE: This method is part of the ChannelGraphSource interface.
|
|
func (r *ChannelRouter) FetchLightningNode(node Vertex) (*channeldb.LightningNode, error) {
|
|
pubKey, err := btcec.ParsePubKey(node[:], btcec.S256())
|
|
if err != nil {
|
|
return nil, fmt.Errorf("unable to parse raw public key: %v", err)
|
|
}
|
|
return r.cfg.Graph.FetchLightningNode(pubKey)
|
|
}
|
|
|
|
// ForEachNode is used to iterate over every node in router topology.
|
|
//
|
|
// NOTE: This method is part of the ChannelGraphSource interface.
|
|
func (r *ChannelRouter) ForEachNode(cb func(*channeldb.LightningNode) error) error {
|
|
return r.cfg.Graph.ForEachNode(nil, func(_ *bbolt.Tx, n *channeldb.LightningNode) error {
|
|
return cb(n)
|
|
})
|
|
}
|
|
|
|
// ForAllOutgoingChannels is used to iterate over all outgoing channels owned by
|
|
// the router.
|
|
//
|
|
// NOTE: This method is part of the ChannelGraphSource interface.
|
|
func (r *ChannelRouter) ForAllOutgoingChannels(cb func(*channeldb.ChannelEdgeInfo,
|
|
*channeldb.ChannelEdgePolicy) error) error {
|
|
|
|
return r.selfNode.ForEachChannel(nil, func(_ *bbolt.Tx, c *channeldb.ChannelEdgeInfo,
|
|
e, _ *channeldb.ChannelEdgePolicy) error {
|
|
|
|
if e == nil {
|
|
return fmt.Errorf("Channel from self node has no policy")
|
|
}
|
|
|
|
return cb(c, e)
|
|
})
|
|
}
|
|
|
|
// ForEachChannel is used to iterate over every known edge (channel) within our
|
|
// view of the channel graph.
|
|
//
|
|
// NOTE: This method is part of the ChannelGraphSource interface.
|
|
func (r *ChannelRouter) ForEachChannel(cb func(chanInfo *channeldb.ChannelEdgeInfo,
|
|
e1, e2 *channeldb.ChannelEdgePolicy) error) error {
|
|
|
|
return r.cfg.Graph.ForEachChannel(cb)
|
|
}
|
|
|
|
// AddProof updates the channel edge info with proof which is needed to
|
|
// properly announce the edge to the rest of the network.
|
|
//
|
|
// NOTE: This method is part of the ChannelGraphSource interface.
|
|
func (r *ChannelRouter) AddProof(chanID lnwire.ShortChannelID,
|
|
proof *channeldb.ChannelAuthProof) error {
|
|
|
|
info, _, _, err := r.cfg.Graph.FetchChannelEdgesByID(chanID.ToUint64())
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
info.AuthProof = proof
|
|
return r.cfg.Graph.UpdateChannelEdge(info)
|
|
}
|
|
|
|
// IsStaleNode returns true if the graph source has a node announcement for the
|
|
// target node with a more recent timestamp.
|
|
//
|
|
// NOTE: This method is part of the ChannelGraphSource interface.
|
|
func (r *ChannelRouter) IsStaleNode(node Vertex, timestamp time.Time) bool {
|
|
// If our attempt to assert that the node announcement is fresh fails,
|
|
// then we know that this is actually a stale announcement.
|
|
return r.assertNodeAnnFreshness(node, timestamp) != nil
|
|
}
|
|
|
|
// IsPublicNode determines whether the given vertex is seen as a public node in
|
|
// the graph from the graph's source node's point of view.
|
|
//
|
|
// NOTE: This method is part of the ChannelGraphSource interface.
|
|
func (r *ChannelRouter) IsPublicNode(node Vertex) (bool, error) {
|
|
return r.cfg.Graph.IsPublicNode(node)
|
|
}
|
|
|
|
// IsKnownEdge returns true if the graph source already knows of the passed
|
|
// channel ID either as a live or zombie edge.
|
|
//
|
|
// NOTE: This method is part of the ChannelGraphSource interface.
|
|
func (r *ChannelRouter) IsKnownEdge(chanID lnwire.ShortChannelID) bool {
|
|
_, _, exists, isZombie, _ := r.cfg.Graph.HasChannelEdge(chanID.ToUint64())
|
|
return exists || isZombie
|
|
}
|
|
|
|
// IsStaleEdgePolicy returns true if the graph soruce has a channel edge for
|
|
// the passed channel ID (and flags) that have a more recent timestamp.
|
|
//
|
|
// NOTE: This method is part of the ChannelGraphSource interface.
|
|
func (r *ChannelRouter) IsStaleEdgePolicy(chanID lnwire.ShortChannelID,
|
|
timestamp time.Time, flags lnwire.ChanUpdateChanFlags) bool {
|
|
|
|
edge1Timestamp, edge2Timestamp, exists, isZombie, err :=
|
|
r.cfg.Graph.HasChannelEdge(chanID.ToUint64())
|
|
if err != nil {
|
|
return false
|
|
|
|
}
|
|
|
|
// If we know of the edge as a zombie, then we'll check the timestamp of
|
|
// this message to determine whether it's fresh.
|
|
if isZombie {
|
|
return time.Since(timestamp) > r.cfg.ChannelPruneExpiry
|
|
}
|
|
|
|
// If we don't know of the edge, then it means it's fresh (thus not
|
|
// stale).
|
|
if !exists {
|
|
return false
|
|
}
|
|
|
|
// As edges are directional edge node has a unique policy for the
|
|
// direction of the edge they control. Therefore we first check if we
|
|
// already have the most up to date information for that edge. If so,
|
|
// then we can exit early.
|
|
switch {
|
|
// A flag set of 0 indicates this is an announcement for the "first"
|
|
// node in the channel.
|
|
case flags&lnwire.ChanUpdateDirection == 0:
|
|
return !edge1Timestamp.Before(timestamp)
|
|
|
|
// Similarly, a flag set of 1 indicates this is an announcement for the
|
|
// "second" node in the channel.
|
|
case flags&lnwire.ChanUpdateDirection == 1:
|
|
return !edge2Timestamp.Before(timestamp)
|
|
}
|
|
|
|
return false
|
|
}
|
|
|
|
// MarkEdgeLive clears an edge from our zombie index, deeming it as live.
|
|
//
|
|
// NOTE: This method is part of the ChannelGraphSource interface.
|
|
func (r *ChannelRouter) MarkEdgeLive(chanID lnwire.ShortChannelID) error {
|
|
return r.cfg.Graph.MarkEdgeLive(chanID.ToUint64())
|
|
}
|